You appear to have missed 21st Century Manufacturing Enterprise Strategy: An Industry-Led View (Volume 1) (Nagel & Dove, 1991), which coined the term agile as it's now used, and the subsequent Agile Competitors and Virtual Organisations (Goldman, Nagel and Priess, 1995), which expanded and defined the concept. Both of which appear to have been where the manifestonauts got the name from, and which at least two of them have described as having the best definitions of agility they'd seen.